Stay-bolt for boilers.



E. l. DQDDS STAY BOLT FOR BOILERS. APPLICATION FILED NOV. 30.- 1914.

Patented Feb. 20,1917.

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ETHAN I. DODDS, OF PIT'ISEBURGI-I, PENNSYLVANIA, ASSIGNGR T0 FLANNERYBOLT COMPANY, OF PITTSBURGH, PENNSYLVANIA.

STAY-BOLT FOR BOILERS.

Application filed November 30, 1914.

To all whom it may concern:

Be it known that I, ETHAN I. Donne, a citizen of the United States, anda resident of Pittsburgh, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inStay-Bolts for Boilers; and I do hereby declare the following to be afull, clear, and exact description of the invention, such. as willenable others skilled. in the art to which it appertains to make and usethe same. I

My invention relates to improvements in stay bolts for boilers, theobject being to provide a bolt that will have greater flexibilityadjacent one head of the bolt than at any other part, so as to localizeor confine the torsional or twistingmovement to such flexible portion.\Vith this end in view my invention consists in the details ofconstruction as will be more fully described and pointed out in theclaims.

In the accompanying drawings, Figure 1 is a view in elevation of thebolt blank after it has been slotted but before it is twisted; Figs. 2,3 and 1 are views in section of the same, the views being takenrespectively on the dotted lines shown in Fig. 1, and Fig. 5 is a viewof the bolt after the shank has been twisted.

In the manufacture of this bolt, a bar of stay bolt metal, perferablycylindrical, is subjected to an upsetting heat and is swaged betweendies having openings therein for the entrance of piercing tools orcutters for piercing or cutting slots in the shank 1 of the bolt. Afterthe slots 2 and?) have been cut, the shank 1 is reduced in diameter asin Fig. 1, and the heads 1 and 4* are formed and threaded in the usualmanner.

The shank 1 of the bolt is slotted approximately throughout its length,so that the entire shank will respond more readily to twisting ortorsional strains than a solid shank, but in order to localize themovement of the shank I have provided the end thereof adjacent the outerhead 4 with a series of slots 3. In the present instance I have shownfour arranged in pairs diametrically opposite each other but stoppingshort of the center, the slots of one pair being at right angles tothose of the other pair. These slots 3 extend from or near the junctureof the head 1 with shank 1, a distance suflicient to provide for thenecessary flexibility of this portion of the shank, while Specificationof Letters Patent.

Patented Feb. 20, 191W.

SeriaI No. 874,823.

the single slot 2 extends from the inner head l of the bolt, to andpreferably slightly be yond the inner edges of the slots 3, as shown inFig. 1. This slot 2 extends all the way through the bolt shank 1, and ofcourse renders this portion of the shank more flexible or yieldable totorsional or twisting strains, than a solid shank, while the pluralityof slots adjacent the outer head divides the shank into a greater numberof parts connected only at their inner ends, and renders this end of theshank more yielding or flexible to torsional or twisting strains than.the other end.

After the blank thus described has been formed, the shank portionthereof is twisted. about 180 as shown in Fig. 5, and the two headsthreaded and the tell-tale (3 bored in the head 4.

In the event of arupture of the bolt at or near the juncture of theshank and head 1, which is the point at which a break usually occurs,the steam or water can escape through the tell-tale and indicate thebreak.

While the exact sequence of the steps may not be essential, I prefer toheat the bar or blank to a mellow heat and shape it in dies or othersuitable'tools'to produce an enlarged head at each end and if desired,also to reduce the diameter of the shank. The shank is then pierced fromopposite sides after which the'slots or impiercements are closed, theshank twisted between its ends and the bolt smoothed and straightenedbetween dies.

A bolt thus constructed is sul'ficiently rigid to withstand alllongitudinal strains either compressive or pulling, to which it. may besub ected 1n ordinary usage, and all torsional or twisting strains towhich it may be subjected in applying it to the sheets, but sufficientlyflexible laterally to accommodate itself to the'lateral twisting ortorsional strains imparted to it by the unequal move- 1 ments of theboiler sheets.

The slots above referred to are not formed by the removal of any of themetal but siniply by cutting or piercing it, so that the capacity of theshank for endwise stresses is not weakened.

Having fully described my invention What I claim as new and desire tosecure by LettersPatent, is

1. As a new article of manufacture, a stay bolt, the shank of which 'isslotted all the 7 V with a plurality of slots adjacent the outer head,the said slots at the two ends of the shank overlapping at the'center.

' 3JAs a new article of manufacture, a

f stay bolt consisting of a shank and two integral heads, 'the'shankbeing slotted all the way through adjacent the inner head and providedwith a plurality of slots extending partway through, adjacent the outerhead.

In testimony whereof, I have signed this 25 specification in thepresence of two subscribing witnesses.

ETHAN I. DODDS.

lVitnesses M. CHARLES BlNGI-IAM, EDWIN SPENCER RYon.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

' Washington, D. c.

